California reported some of the earliest coronavirus cases in the United States in late January. And in the first week of March, California and New York were neck and neck on cases of COVID-19, the disease caused by the coronavirus. But over the past week, New York case counts have doubled every few days, and the state now has nearly 10 times the cases California does: 38,000 to 4,200.

Infectious-disease experts say early maneuvers in California, especially in the Bay Area — first discouraging people from gathering in crowds and then ordering them to shelter in place — may have had a dramatic impact, even if they came only a few days ahead of those in New York.

But other factors may also be in play. New York is testing far more people — three times as many as California — and therefore identifying more cases, for example. And it’s possible that what’s happening 3,000 miles away could be California’s future.